The present invention relates to new containers useful in a variety of applications. In a specific example, the containers can be used for growing cell cultures. These cells may be plant or animal cultures.
As the biotechnology, agricultural, and medical fields have advanced there has been an increasing need for growing cells in culture. The growth of cells in culture provides a controlled setting for growth of sensitive cells, genetically transformed cells, or other cells needing careful attention and/or a controlled environment.
Cell culture media is typically a solution of nutrients, amino acids, electrolytes, and/or vitamins. The solution may be supplemented with any of a large number of components including, for example, fetal bovine serum, which is believed to contain growth factors and other proteins that are essential to mammalian cell growth. Media is typically sold in either a liquid or powder form. If the media is sold in a powder form, it must be reconstituted prior to use.
Typically, liquid cell culture media is packaged and used in rigid bottles, or containers. Glass bottles are used to package the cell culture media because of their barrier properties. Because amino acids are readily oxidized an oxygen barrier is needed. Furthermore, a carbon dioxide barrier is needed because typically a bicarbonate buffer system is used in the media. Moreover, it is critical that the interior surface of the container is inert because of the sensitivities of the cells to toxic leachables.
In the growing of cell cultures, it is likely that the grower will want to provide various growth conditions at various stages of growth. Such conditions may include, for example, a condition under which the container is hermetically sealed, a condition under which the container is allowed to breathe only to a very limited extent, and a condition under which air is allowed to pass freely into and out of the closed container.
Researchers and commercial production facilities have used a variety of containers to grow cell cultures. For example, it is common for cell cultures to be grown in rigid plastic containers having a separate lid which screws or snaps onto the open top of the vessel. Alternatively, the open top of the vessel may be covered by a flexible plastic material such as parafilm. Sometimes test tubes or plastic or glass flasks are used to grow cell cultures. Typically, such test tubes or flasks will be fitted with an appropriate stopper such as a rubber stopper.
The process of utilizing rigid containers for cell culture procedures has some clear disadvantages. Of course, the storage of rigid containers utilizes a large amount of space. Prior to use, the bottles must be washed and sterilized. Moreover, when glass containers are used, there is a possibility that the bottles will break or be damaged during handling.
Additionally, the typical techniques of transferring tissue or cell cultures from container to container are time consuming and have a risk of contamination. Still a further disadvantage in using glass and plastic rigid bottles is that there is a problem of disposing of the container after it has been emptied. An additional disadvantage of using traditional containers is the cost associated with the handling of and the pre-filling processing of the containers.
A further disadvantage of using rigid reusable cell culture vessels is the time, effort, and expensive involved in washing and sterilizing these vessels. It is very important to avoid contamination in cell culture procedures and, therefore, it is critical to thoroughly clean and sterilize the vessels between uses. Such cleaning procedures are labor intensive and add to the cost of cell culture procedures.
Accordingly, there is a need for an improved container for containing cell culture media. Containers are also needed in a variety of other applications where it is desired to have an inexpensive, lightweight receptacle.
A principal object of the present invention is to provide an economical container which is easily used. Economy is not only present insofar as the cost of manufacture is concerned but also from the standpoint of efficient use of the area or space occupied by the containers. In the particular case of cell or tissue culture, an additional consideration for the grower is the problem of sterilizing the vessel and media between uses; the present invention overcomes this problem.